Witnesses told police that a man poured liquid -- possibly a beverage containing alcohol -- on the sleeping woman at about 1 a.m. outside a Walgreens store near Van Nuys Boulevard and Sherman Way. He lit a match and ran from the location, witnesses told police.

The woman, who is in her 60s, was hospitalized in critical condition. The victim will likely be transported to a Sherman Oaks burn center for treatment, police said.

"It was like when you pour gasoline on something -- like an explosion," said witness Erickson Ipina, who added that he often saw the homeless woman in the neighborhood.

The man purchased the bottle containing alcohol in the Walgreens store, then poured the contents on the woman, Ipina told a Newsreel photographer. Ipina said he called 911 and followed the attacker, who brandished a knife.

"He told me, 'Stop following me, or I will cut you,'" Ipina said. "I kept following him and then the police came."